XYLANASE-IV, AN EXOXYLANASE OF AEROMONAS-CAVIAE ME-1 WHICH PRODUCES XYLOTETRAOSE AS THE ONLY LOW-MOLECULAR-WEIGHT OLIGOSACCHARIDE FROM XYLAN

A novel xylanase (xylanase IV) which produces xylotetmose as the only low-molecular-weight oligosaccharide from oat spelt xylan was isolated from the culture medium of Aeromonas caviae ME-1. By sodium dodecyl s ulfate-polyacrylamide gel electrophoresis, the xylanase IV molecular w eight was 41,000. Xylanase IV catalyzed the hydrolysis of oat spelt xy lan, producing exclusively xylotetraose. The acid hydrolysate of the p roduct gave D-xylose. The enzyme did not hydrolyze either p-nitropheny l-beta-D-xyloside, small oligosaccharides (xylobiose and xylotetraose) , or polysaccharides, such as starch, cellulose, carboxymethyl cellulo se, laminarin, and beta-1,3-xylan.